
    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
      <meta charset="UTF-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <title>InheritableThreadLoca90%开发者踩过的坑 - 交互式测验</title>
      <style>
        @import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;700&display=swap');
        
        body {
          font-family: 'Noto Sans SC', sans-serif;
          background-color: #f4f7f9;
          color: #333;
          display: flex;
          justify-content: center;
          align-items: center;
          min-height: 100vh;
          margin: 0;
          padding: 20px;
          box-sizing: border-box;
        }
        
        .main-wrapper {
            position: relative;
            width: 100%;
            max-width: 900px; /* Wider to accommodate buttons */
            display: flex;
            justify-content: center;
            align-items: center;
        }

        .quiz-container {
          background-color: #ffffff;
          border-radius: 16px;
          box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
          width: 100%;
          max-width: 700px;
          overflow: hidden;
          z-index: 10;
        }

        .quiz-header {
          background-color: #4a90e2;
          color: white;
          padding: 20px 30px;
          text-align: center;
        }

        .quiz-header h1 {
          margin: 0;
          font-size: 24px;
          font-weight: 700;
        }
        
        .quiz-header p {
            margin: 5px 0 0;
            font-size: 14px;
            opacity: 0.9;
        }

        .quiz-body {
          padding: 30px;
        }

        .progress-bar {
            display: none; /* 隐藏进度条 */
            width: 100%;
            background-color: #e0e0e0;
            border-radius: 5px;
            height: 10px;
            margin-bottom: 20px;
        }

        #progress-indicator {
            height: 100%;
            width: 0%;
            background-color: #4caf50;
            border-radius: 5px;
            transition: width 0.3s ease;
        }

        #question-container {
          margin-bottom: 20px;
        }

        #question-text {
          font-size: 18px;
          font-weight: 500;
          line-height: 1.6;
          margin-bottom: 25px;
        }

        .options-list {
          list-style: none;
          padding: 0;
          margin: 0;
        }

        .option-item {
          background-color: #f8f9fa;
          border: 1px solid #dee2e6;
          border-radius: 8px;
          padding: 15px;
          margin-bottom: 12px;
          cursor: pointer;
          transition: background-color 0.2s ease, border-color 0.2s ease;
        }

        .option-item:hover {
          background-color: #e9ecef;
        }
        
        .option-item.selected {
            background-color: #d1e7fd;
            border-color: #4a90e2;
        }

        .quiz-footer {
          padding: 20px 30px;
          display: flex;
          justify-content: space-between; /* 将按钮分布在两侧 */
          align-items: center;
          min-height: 65px; /* Reserve space */
        }

        .nav-btn {
          background-color: #4a90e2;
          color: white;
          border: none;
          border-radius: 8px;
          padding: 10px 20px;
          font-size: 16px;
          font-weight: 500;
          cursor: pointer;
          transition: background-color 0.2s ease, transform 0.2s ease;
          box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        }
        
        #next-btn {
            background-color: #28a745;
        }

        .nav-btn:hover {
          background-color: #357abd;
          transform: scale(1.05);
        }
        
        .nav-btn:disabled {
            background-color: #a0c3e8;
            cursor: not-allowed;
            opacity: 0.7;
        }

        #result-container {
            border-top: 1px solid #eee;
        }
        
        .result-box {
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
        }
        
        .result-box.correct {
            background-color: #d4edda;
            border: 1px solid #c3e6cb;
            color: #155724;
        }

        .result-box.incorrect {
            background-color: #f8d7da;
            border: 1px solid #f5c6cb;
            color: #721c24;
        }
        
        .result-box h3 {
            margin-top: 0;
        }

        .explanation-text {
            margin-top: 15px;
            line-height: 1.7;
        }
        
        .source-text {
            font-style: italic;
            font-size: 14px;
            margin-top: 15px;
            color: #555;
        }

        
        .final-score-container {
            padding: 40px;
            text-align: center;
        }
        .final-score-container h2 {
            margin-top: 0;
            margin-bottom: 30px;
        }
        .score-summary {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-bottom: 40px;
            flex-wrap: wrap;
        }
        .score-card {
            background-color: #f8f9fa;
            border-radius: 12px;
            padding: 20px;
            width: 180px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
            border: 1px solid #e9ecef;
        }
        .score-card h3 {
            margin: 0 0 10px;
            font-size: 16px;
            font-weight: 500;
            color: #555;
        }
        .score-card p {
            margin: 0;
            font-size: 28px;
            font-weight: 700;
            color: #333;
        }
        .score-details table {
            width: 100%;
            font-size: 16px;
        }
        .score-details td {
            padding: 4px 0;
        }
        .score-details td:last-child {
            text-align: right;
            font-weight: 700;
        }
        .report-actions button {
            background-color: #fff;
            border: 1px solid #ccc;
            border-radius: 8px;
            padding: 12px 25px;
            font-size: 16px;
            cursor: pointer;
            margin: 0 10px;
            transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
        }
        .report-actions button:hover {
            background-color: #f1f1f1;
            border-color: #bbb;
            transform: translateY(-2px);
        }
        .report-actions button.primary {
            background-color: #28a745;
            color: white;
            border-color: #28a745;
        }
        .report-actions button.primary:hover {
            background-color: #218838;
        }
        
        .hint-container {
            background-color: #e0f7fa;
            border: 1px solid #b2ebf2;
            border-radius: 8px;
            padding: 15px;
            margin-top: 20px;
            color: #006064;
            font-size: 15px;
            line-height: 1.6;
            display: none; /* 默认隐藏 */
        }
      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>InheritableThreadLoca90%开发者踩过的坑 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "InheritableThreadLocal 主要解决了 ThreadLocal 在哪种特定场景下的不足？",
    "options": [
      "在多线程环境下保证不同线程间数据的绝对隔离。",
      "在父子线程创建时，需要自动传递上下文数据的场景。",
      "在线程池中高效复用线程时的数据传递问题。",
      "解决高并发下由线程局部变量引起的内存泄漏问题。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "ThreadLocal 的核心功能是实现线程内部的数据隔离，但它无法将数据从父线程传递给子线程。InheritableThreadLocal 正是为了解决这个问题而设计的，它通过在子线程创建时复制父线程的 inheritableThreadLocals 映射，实现了上下文数据的自动继承。",
    "source": "文档中「1.1：从ThreadLocal到InheritableThreadLocal的演进」部分",
    "hint": "回想一下文档开头的代码示例，当使用普通 ThreadLocal 时，子线程为什么打印出 `null`？"
  },
  {
    "question": "在线程池（如 ExecutorService）环境中使用 InheritableThreadLocal 时，最可能遇到的核心问题是什么？",
    "options": [
      "因为线程池会主动清除所有线程局部变量，导致数据丢失。",
      "因为线程池的核心机制是复用线程，InheritableThreadLocal 的值只在线程首次创建时继承，后续任务复用该线程时不会再次更新。",
      "因为向线程池提交任务的父线程在任务执行前就已结束，导致其上下文数据被垃圾回收。",
      "因为 InheritableThreadLocal 自身存在设计缺陷，无法在超过一个子线程的环境下工作。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "InheritableThreadLocal 的数据传递机制发生在线程的 `init` 方法中，即仅在线程被`new`出来的时候。线程池为了效率会复用已经创建的线程，而不是为每个新任务都创建新线程。因此，当一个任务被分配给一个被复用的旧线程时，该线程不会再次从提交任务的父线程那里继承上下文，可能导致数据不一致或拿到之前任务的脏数据。",
    "source": "文档中「4.1：线程池环境下的数据丢失问题」部分",
    "hint": "文档中明确指出：“线程池中的线程是复用的，不会重新创建，因此数据传递失效”。"
  },
  {
    "question": "根据文档中的代码示例，当 InheritableThreadLocal 存储一个可变对象（如 User 对象）时，它在父子线程间的数据传递默认采用的是什么机制？这会带来什么后果？",
    "options": [
      "深拷贝；子线程修改对象状态不会影响父线程。",
      "浅拷贝；子线程对该对象的任何修改都会反映在父线程中。",
      "序列化拷贝；父子线程的对象完全独立，但性能开销较大。",
      "值拷贝；子线程得到的是一个不可变副本，无法修改。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "InheritableThreadLocal 在传递数据时，默认只复制了对象的引用（即浅拷贝），而不是创建一个全新的对象副本。这意味着父线程和子线程的 InheritableThreadLocal 都指向堆内存中的同一个对象实例。因此，如果子线程通过这个引用修改了对象的内部状态（例如调用了 `setName` 方法），父线程通过自己的引用访问该对象时，也会看到这个变化。",
    "source": "文档中「2.3：浅拷贝与深拷贝的区别」部分",
    "hint": "思考一下文档中那个 `User` 对象的名字从“张三”变为“李四”的例子。"
  },
  {
    "question": "如果你希望子线程继承到的值不是父线程的原始值，而是经过某种特定逻辑处理后的新值（例如，为 traceId 添加一个子线程后缀），你应该通过重写 InheritableThreadLocal 的哪个方法来实现？",
    "options": [
      "initialValue()",
      "createInheritedMap(ThreadLocalMap parentMap)",
      "set(T value)",
      "childValue(T parentValue)"
    ],
    "correctAnswerIndex": 3,
    "explanation": "文档明确指出 `childValue` 方法是 InheritableThreadLocal 提供的扩展点。在创建子线程并复制 `inheritableThreadLocals` 映射的过程中，系统会为每一个条目调用其键（即 InheritableThreadLocal 实例）的 `childValue` 方法。该方法的参数是父线程中的值，其返回值将作为子线程中对应的值。",
    "source": "文档中「6.2：childValue方法的扩展点」部分",
    "hint": "文档中的 `CustomInheritableThreadLocal` 示例展示了如何重写一个方法来改变子线程获取到的值。"
  },
  {
    "question": "为了防止在使用 InheritableThreadLocal 时可能发生的内存泄漏，文档推荐的最佳实践是什么？",
    "options": [
      "依赖JVM的垃圾回收机制，因为它会自动处理不再使用的线程局部变量。",
      "在线程执行完毕后，将 InheritableThreadLocal 实例本身设置为 `null`。",
      "在 finally 代码块中调用 InheritableThreadLocal 实例的 `remove()` 方法。",
      "只在 InheritableThreadLocal 中存储基本数据类型，避免存储对象引用。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "当线程被复用时（如在线程池中），它所关联的 ThreadLocalMap 会一直存在。如果不手动调用 `remove()` 方法，那么存储在 Map 中的值对象将持续被引用，无法被垃圾回收，从而导致内存泄漏。将清理操作放在 `finally` 块中，可以确保无论业务逻辑是否正常完成或抛出异常，`remove()` 方法都会被执行，这是最安全可靠的方式。",
    "source": "文档中「4.3：内存泄漏的预防措施」部分",
    "hint": "文档中的 `MemoryLeakPreventionDemo` 示例代码结构是怎样的？"
  },
  {
    "question": "根据文档「实战应用场景」章节的描述，以下哪一项**不属于** InheritableThreadLocal 的典型应用场景？",
    "options": [
      "在分布式系统中，跨越多个服务调用传递链路追踪ID（traceId）。",
      "在Spring应用中，将事务上下文从主线程传播到新启动的异步任务中。",
      "在线程间共享需要高频更新的大体积缓存数据。",
      "在Web请求处理过程中，将当前登录用户的认证信息传递给业务逻辑中创建的子线程。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "InheritableThreadLocal 主要用于传递小体积的、与请求或线程生命周期绑定的“上下文”数据。对于大体积或需要高频更新的共享缓存数据，使用 InheritableThreadLocal 会因其拷贝机制带来性能问题和数据一致性挑战，这种场景更适合使用如 ConcurrentHashMap 或专业的分布式缓存解决方案。",
    "source": "文档中「3：实战应用场景」和「5.1：合理使用InheritableThreadLocal的时机」部分",
    "hint": "文档在「合理使用」一节中明确提到了 InheritableThreadLocal 的适用场景和不适用场景，其中之一就与数据量有关。"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

        function loadQuestion() {
          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
          if (currentQuestionIndex >= quizData.length) {
            showFinalScore();
            return;
          }

          updateProgress();

          const currentQuestion = quizData[currentQuestionIndex];
          questionTextEl.textContent = `(${currentQuestionIndex + 1}/${quizData.length}) ${currentQuestion.question}`;
          
          currentQuestion.options.forEach((optionText, index) => {
            const li = document.createElement('li');
            li.className = 'option-item';
            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
                }
            }
            optionsListEl.appendChild(li);
          });

          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
          }
          
          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
            }, 0);

            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
        }
        
        function updateProgress() {
            const answeredQuestions = userAnswers.filter(answer => answer !== null).length;
            const progressPercentage = (answeredQuestions / quizData.length) * 100;
            progressIndicatorEl.style.width = `${progressPercentage}%`;
        }
        
        function updateNavigationButtons() {
            prevBtn.style.display = 'block';
            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
            Array.from(optionsListEl.children).forEach((child, index) => {
                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
            });
        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

        function goToPreviousQuestion() {
            if (currentQuestionIndex > 0) {
                currentQuestionIndex--;
                loadQuestion();
            }
        }
        
        function showHint() {
            const currentQuestion = quizData[currentQuestionIndex];
            if (currentQuestion.hint) {
                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  